diff options
Diffstat (limited to 'src/include/statistics/statistics.h')
| -rw-r--r-- | src/include/statistics/statistics.h | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/src/include/statistics/statistics.h b/src/include/statistics/statistics.h index 4876e9523f6..57998810755 100644 --- a/src/include/statistics/statistics.h +++ b/src/include/statistics/statistics.h @@ -78,8 +78,41 @@ typedef struct MVDependencies /* size of the struct excluding the deps array */ #define SizeOfDependencies (offsetof(MVDependencies, ndeps) + sizeof(uint32)) +/* used to flag stats serialized to bytea */ +#define STATS_MCV_MAGIC 0xE1A651C2 /* marks serialized bytea */ +#define STATS_MCV_TYPE_BASIC 1 /* basic MCV list type */ + +/* max items in MCV list (mostly arbitrary number) */ +#define STATS_MCVLIST_MAX_ITEMS 8192 + +/* + * Multivariate MCV (most-common value) lists + * + * A straightforward extension of MCV items - i.e. a list (array) of + * combinations of attribute values, together with a frequency and null flags. + */ +typedef struct MCVItem +{ + double frequency; /* frequency of this combination */ + double base_frequency; /* frequency if independent */ + bool *isnull; /* NULL flags */ + Datum *values; /* item values */ +} MCVItem; + +/* multivariate MCV list - essentally an array of MCV items */ +typedef struct MCVList +{ + uint32 magic; /* magic constant marker */ + uint32 type; /* type of MCV list (BASIC) */ + uint32 nitems; /* number of MCV items in the array */ + AttrNumber ndimensions; /* number of dimensions */ + Oid types[STATS_MAX_DIMENSIONS]; /* OIDs of data types */ + MCVItem **items; /* array of MCV items */ +} MCVList; + extern MVNDistinct *statext_ndistinct_load(Oid mvoid); extern MVDependencies *statext_dependencies_load(Oid mvoid); +extern MCVList *statext_mcv_load(Oid mvoid); extern void BuildRelationExtStatistics(Relation onerel, double totalrows, int numrows, HeapTuple *rows, @@ -92,6 +125,13 @@ extern Selectivity dependencies_clauselist_selectivity(PlannerInfo *root, SpecialJoinInfo *sjinfo, RelOptInfo *rel, Bitmapset **estimatedclauses); +extern Selectivity statext_clauselist_selectivity(PlannerInfo *root, + List *clauses, + int varRelid, + JoinType jointype, + SpecialJoinInfo *sjinfo, + RelOptInfo *rel, + Bitmapset **estimatedclauses); extern bool has_stats_of_kind(List *stats, char requiredkind); extern StatisticExtInfo *choose_best_statistics(List *stats, Bitmapset *attnums, char requiredkind); |